The Cost of Not Retesting: Human Immunodeficiency Virus Misdiagnosis in the Antiretroviral Therapy "Test-and-Offer" Era

Evaluation of the Nigeria national HIV rapid testing algorithm

Human Immunodeficiency Virus (HIV) diagnosis remains the gateway to HIV care and treatment. However, due to changes in HIV prevalence and testing coverage across different geopolitical zones, it is crucial to evaluate the national HIV testing algorithm as false positivity due to low prevalence could be detrimental to both the client and the service delivery. Therefore, we evaluated the performance of the national HIV rapid testing algorithm using specimens collected from multiple HIV testing services (HTS) sites and compared the results from different HIV prevalence levels across the six geopolitical zones of Nigeria. The evaluation employed a dual approach, retrospective, and prospective. The retrospective evaluation focused on a desktop review of program data (n = 492,880) collated from patients attending routine HTS from six geopolitical zones of Nigeria between January 2017 and December 2019. The prospective component utilized samples (n = 2,895) collected from the field at the HTS and tested using the current national serial HIV rapid testing algorithm. These samples were transported to the National Reference Laboratory (NRL), Abuja, and were re-tested using the national HIV rapid testing algorithm and HIV-1/2 supplementary assays (Geenius to confirm positives and resolve discordance and multiplex assay). The retrospective component of the study revealed that the overall proportion of HIV positives, based on the selected areas, was 5.7% (28,319/492,880) within the study period, and the discordant rate between tests 1 and 2 was 1.1%. The prospective component of the study indicated no significant differences between the test performed at the field using the national HIV rapid testing algorithm and the re-testing performed at the NRL. The comparison between the test performed at the field using the national HIV rapid testing algorithm and Geenius HIV-1/2 supplementary assay showed an agreement rate of 95.2%, while that of the NRL was 99.3%. In addition, the comparison of the field results with HIV multiplex assay indicated a sensitivity of 96.6%, the specificity of 98.2%, PPV of 97.0%, and Kappa Statistic of 0.95, and that of the NRL with HIV multiplex assay was 99.2%, 99.4%, 99.0%, and 0.99, respectively. Results show that the Nigeria national serial HIV rapid testing algorithm performed very well across the target settings. However, the algorithm's performance in the field was lower than the performance outcomes under a controlled environment in the NRL. There is a need to target testers in the field for routine continuous quality improvement implementation, including refresher trainings as necessary.

The Effects of Workplace-Based HIV Self-testing on Uptake of Testing and Linkage to HIV Care or Prevention by Men in Uganda (WISe-Men): Protocol for a Cluster Randomized Trial

BACKGROUND

HIV testing uptake remains low among men in sub-Saharan Africa. HIV self-testing (HIVST) at the workplace is a novel approach to increase the availability of, and access to, testing among men. However, both access and linkage to posttest services remain a challenge.

OBJECTIVE

The aim of this protocol is to describe a cluster randomized trial (CRT)-Workplace-Based HIV Self-testing Among Men (WISe-Men)-to evaluate the effect of HIVST in workplace settings on the uptake of HIV testing services (HTS) and linkage to treatment and prevention services among men employed in private security services in Uganda.

METHODS

This is a two-arm CRT involving men employed in private security services in two Ugandan districts. The participants in the intervention clusters will undergo workplace-based HIVST using OraQuick test kits. Those in the control clusters will receive routine HTS at their work premises. In addition to HTS, participants in both the intervention and control arms will undergo other tests and assessments, which include blood pressure assessment, blood glucose and BMI measurement, and rapid diagnostic testing for syphilis. The primary outcome is the uptake of HIV testing. The secondary outcomes include HIV status reporting, linkage into HIV care and confirmatory testing following HIVST, initiation of antiretroviral therapy following a confirmatory HIV test, the uptake of voluntary medical male circumcision, consistent condom use, and the uptake of pre-exposure prophylaxis by the most at-risk populations.

RESULTS

Participant enrollment commenced in February 2020, and the trial is still recruiting study participants. Follow-up for currently enrolled participants is ongoing. Data collection and analysis is expected to be completed in December 2021.

CONCLUSIONS

The WISe-Men trial will provide information regarding whether self-testing at worksites increases the uptake of HIV testing as well as the linkage to care and prevention services at male-dominated workplaces in Uganda. Additionally, the findings will help us propose strategies for improving men's engagement in HTS and ways to improve linkage to further care following a reactive or nonreactive HIVST result.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04164433; https://clinicaltrials.gov/ct2/show/NCT04164433.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/25099.

HIV-1 diagnosis using dried blood spots from patients in Kinshasa, DRC: a tool to detect misdiagnosis and achieve World Health Organization 2030 targets

INTRODUCTION

Currently, only 54% of the population of the Democratic Republic of the Congo (DRC) know their HIV status. The aim of this study was to detect HIV misdiagnosis from rapid diagnostic tests (RDT) and to evaluate serological immunoassays using dried blood spots (DBS) from patients in Kinshasa, DRC.

METHODS

Between 2016 and 2018, 365 DBS samples were collected from 363 individuals and shipped to Spain. The samples were from people with a new HIV positive (n = 123) or indeterminate (n = 23) result, known HIV-positive patients (n = 157), and a negative control group (n = 62). HIV serology was performed using Elecsys HIV combi PT (Roche), VIDAS HIV Duo Quick (BioMérieux), and Geenius (Bio-Rad). In addition, HIV RNA detection was performed in all samples using the COBAS AmpliPrep/COBAS Taqman HIV-1 Test 2.0 (Roche).

RESULTS

Overall, 272 samples were found to be positive and 93 to be negative for HIV serology. The sensitivity was 100% for both Elecsys and VIDAS techniques, but specificity was slightly higher for the VIDAS test: 100% (96.1-100%) vs 98.9% (94.1-99.9%). Of the 23 indeterminate cases using RDT, only three cases were true-positives with a detectable viral load. Eleven samples out of the 280 classified as positive by RDT corresponded to nine patients who had received a false diagnosis of HIV through RDT (3.9%); six of them had been on antiretroviral therapy for at least 2 years.

CONCLUSIONS

Elecsys HIV combi PT and VIDAS HIV Duo Quick immunoassays showed high sensitivity and specificity when using DBS. RDT-based serological diagnosis can lead to HIV misdiagnosis with personal and social consequences in sub-Saharan Africa.

Country adherence to WHO recommendations to improve the quality of HIV diagnosis: a global policy review

Introduction

Ensuring a correct and timely HIV diagnosis is critical. WHO publishes guidelines on HIV testing strategies that maximise the likelihood of correctly determining one’s HIV status. A review of national HIV testing policies in 2014 found low adherence to WHO guidelines. We updated this review to determine adherence to current recommendations.

Methods

We conducted a comprehensive policy review through April 2018. We extracted data on HIV testing strategies, recommendations on HIV retesting prior to antiretroviral therapy (ART) initiation and pre-exposure prophylaxis (PrEP)-related HIV testing information. Descriptive analyses disaggregated by region were conducted to ascertain adherence to recommendations and to describe testing strategy characteristics.

Results

Of 91 policies included, 26% (n=24/91) adhered to WHO recommendations. Having a two-assay testing strategy to rule-in HIV infection as opposed to the recommended three-assay testing strategy was a major reason for non-adherence. Of 72 country policies providing sufficient information, 31% (n=22) recommended retesting for HIV prior to initiating ART. Of 25 countries and two regions reporting PrEP-related HIV testing guidelines, almost all recommended testing prior to initiating PrEP and every 3 months during PrEP use.

Conclusions

Global adherence to WHO recommendations for HIV testing strategies have improved since 2014 but remain low. We found adherence existed on a continuum. Such a system provides insights into how countries can move towards adherence by making relatively minor changes to testing strategies. Guidance from WHO on the role of new HIV testing technologies within testing algorithms and identifying ways to simplify testing guidance is warranted.

Evaluating Point-of-Care Nucleic Acid Tests in Adult Human Immunodeficiency Virus Diagnostic Strategies: A Côte d'Ivoire Modeling Analysis

BACKGROUND

The World Health Organization (WHO) human immunodeficiency virus (HIV) diagnostic strategy requires 6 rapid diagnostic tests (RDTs). Point-of-care nucleic acid tests (POC NATs) are costlier, less sensitive, but more specific than RDTs.

METHODS

We simulated a 1-time screening process in Côte d'Ivoire (CI; undiagnosed prevalence: 1.8%), comparing WHO- and CI-recommended RDT-based strategies (RDT-WHO, RDT-CI) and an alternative: POC NAT to resolve RDT discordancy (NAT-Resolve). Costs included assays (RDT: $1.47; POC NAT: $27.92), antiretroviral therapy ($6-$22/month), and HIV care ($27-$38/month). We modeled 2 sensitivity/specificity scenarios: high-performing (RDT: 99.9%/99.1%; POC NAT: 95.0%/100.0%) and low-performing (RDT: 91.1%/82.9%; POC NAT: 93.3%/99.5%). Outcomes included true-positive (TP), false-positive (FP), true-negative (TN), or false-negative (FN) results; life expectancy; costs; and incremental cost-effectiveness ratios (ICERs: $/year of life saved [YLS]; threshold ≤$1720/YLS [per-capita gross domestic product]).

RESULTS

Model-projected impacts of misdiagnoses were 4.4 years lost (FN vs TP; range, 3.0-13.0 years) and a $5800 lifetime cost increase (FP vs TN; range, $590-$14 680). In the high-performing scenario, misdiagnoses/10 000 000 tested were lowest for NAT-Resolve vs RDT-based strategies (FN: 409 vs 413-429; FP: 14 vs 21-28). Strategies had similar life expectancy (228 months) and lifetime costs ($220/person) among all tested; ICERs were $3450/YLS (RDT-CI vs RDT-WHO) and $120 910/YLS (NAT-Resolve vs RDT-CI). In the low-performing scenario, misdiagnoses were higher (FN: 22 845-30 357; FP: 83 724-112 702) and NAT-Resolve was cost-saving.

CONCLUSIONS

We projected substantial clinical and economic impacts of misdiagnoses. Using POC NAT to resolve RDT discordancy generated the fewest misdiagnoses and was not cost-effective in high-performing scenarios, but may be an important adjunct to existing RDT-based strategies in low-performing scenarios.

The potential for quality assurance systems to save costs and lives: the case of early infant diagnosis of HIV

OBJECTIVES

Scaling up of point-of-care testing (POCT) for early infant diagnosis of HIV (EID) could reduce the large gap in infant testing. However, suboptimal POCT EID could have limited impact and potentially high avoidable costs. This study models the cost-effectiveness of a quality assurance system to address testing performance and screening interruptions, due to, for example, supply stockouts, in Kenya, Senegal, South Africa, Uganda and Zimbabwe, with varying HIV epidemics and different health systems.

METHODS

We modelled a quality assurance system-raised EID quality from suboptimal levels: that is, from misdiagnosis rates of 5%, 10% and 20% and EID testing interruptions in months, to uninterrupted optimal performance (98.5% sensitivity, 99.9% specificity). For each country, we estimated the 1-year impact and cost-effectiveness (US$/DALY averted) of improved scenarios in averting missed HIV infections and unneeded HIV treatment costs for false-positive diagnoses.

RESULTS

The modelled 1-year costs of a national POCT quality assurance system range from US$ 69 359 in South Africa to US$ 334 341 in Zimbabwe. At the country level, quality assurance systems could potentially avert between 36 and 711 missed infections (i.e. false negatives) per year and unneeded treatment costs between US$ 5808 and US$ 739 030.

CONCLUSIONS

The model estimates adding effective quality assurance systems are cost-saving in four of the five countries within the first year. Starting EQA requires an initial investment but will provide a positive return on investment within five years by averting the costs of misdiagnoses and would be even more efficient if implemented across multiple applications of POCT.

Cost implications of HIV retesting for verification in Africa

INTRODUCTION

HIV misdiagnosis leads to severe individual and public health consequences. Retesting for verification of all HIV-positive cases prior to antiretroviral therapy initiation can reduce HIV misdiagnosis, yet this practice has not been not widely implemented.

METHODS

We evaluated and compared the cost of retesting for verification of HIV seropositivity (retesting) to the cost of antiretroviral treatment (ART) for misdiagnosed cases in the absence of retesting (no retesting), from the perspective of the health care system. We estimated the number of misdiagnosed cases based on a review of misdiagnosis rates, and the number of positives persons needing ART initiation by 2020. We presented the total and per person costs of retesting as compared to no retesting, over a ten-year horizon, across 50 countries in Africa grouped by income level. We conducted univariate sensitivity analysis on all model input parameters, and threshold analysis to evaluate the parameter values where the total costs of retesting and the costs no retesting are equivalent. Cost data were adjusted to 2017 United States Dollars.

RESULTS AND DISCUSSION

The estimated number of misdiagnoses, in the absence of retesting was 156,117, 52,720 and 29,884 for lower-income countries (LICs), lower-middle income countries (LMICs), and upper middle-income countries (UMICs), respectively, totaling 240,463 for Africa. Under the retesting scenario, costs per person initially diagnosed were: $40, $21, and $42, for LICs, LMICs, and UMICs, respectively. When retesting for verification is implemented, the savings in unnecessary ART were $125, $43, and $75 per person initially diagnosed, for LICs, LMICs, and UMICs, respectively. Over the ten-year horizon, the total costs under the retesting scenario, over all country income levels, was $475 million, and was $1.192 billion under the no retesting scenario, representing total estimated savings of $717 million in HIV treatment costs averted.

CONCLUSIONS

Results show that to reduce HIV misdiagnosis, countries in Africa should implement the WHO's recommendation of retesting for verification prior to ART initiation, as part of a comprehensive quality assurance program for HIV testing services.

Optimizing HIV testing services in sub-Saharan Africa: cost and performance of verification testing with HIV self-tests and tests for triage

INTRODUCTION

Strategies employing a single rapid diagnostic test (RDT) such as HIV self-testing (HIVST) or "test for triage" (T4T) are proposed to increase HIV testing programme impact. Current guidelines recommend serial testing with two or three RDTs for HIV diagnosis, followed by retesting with the same algorithm to verify HIV-positive status before anti-retroviral therapy (ART) initiation. We investigated whether clients presenting to HIV testing services (HTS) following a single reactive RDT must undergo the diagnostic algorithm twice to diagnose and verify HIV-positive status, or whether a diagnosis with the setting-specific algorithm is adequate for ART initiation.

METHODS

We calculated (1) expected number of false-positive (FP) misclassifications per 10,000 HIV negative persons tested, (2) positive predictive value (PPV) of the overall HIV testing strategy compared to the WHO recommended PPV ≥99%, and (3) expected cost per FP misclassified person identified by additional verification testing in a typical low-/middle-income setting, compared to the expected lifetime ART cost of $3000. Scenarios considered were as follows: 10% prevalence using two serial RDTs for diagnosis, 1% prevalence using three serial RDTs, and calibration using programmatic data from Malawi in 2017 where the proportion of people testing HIV positive in facilities was 4%.

RESULTS

In the 10% HIV prevalence setting with a triage test, the expected number of FP misclassifications was 0.86 per 10,000 tested without verification testing and the PPV was 99.9%. In the 1% prevalence setting, expected FP misclassifications were 0.19 with 99.8% PPV, and in the Malawi 2017 calibrated setting the expected misclassifications were 0.08 with 99.98% PPV. The cost per FP identified by verification testing was $5879, $3770, and $24,259 respectively. Results were sensitive to assumptions about accuracy of self-reported reactive results and whether reactive triage test results influenced biased interpretation of subsequent RDT results by the HTS provider.

CONCLUSIONS

Diagnosis with the full algorithm following presentation with a reactive triage test is expected to achieve PPV above the 99% threshold. Continuing verification testing prior to ART initiation remains recommended, but HIV testing strategies involving HIVST and T4T may provide opportunities to maintain quality while increasing efficiency as part of broader restructuring of HIV testing service delivery.

Audit of HIV counselling and testing services among primary healthcare facilities in Cameroon: a protocol for a multicentre national cross-sectional study

INTRODUCTION

HIV testing is an invaluable entry point to prevention, care and treatment services for people living with HIV and AIDS. Poor adherence to recommended protocols and guidelines reduces the performance of rapid diagnostic tests, leading to misdiagnosis and poor estimation of HIV seroprevalence. This study seeks to evaluate the adherence of primary healthcare facilities in Cameroon to recommended HIV counselling and testing (HCT) procedures and the impact this may have on the reliability of HIV test results.

METHODS AND ANALYSIS

This will be an analytical cross-sectional study involving primary healthcare facilities from all the 10 regions of Cameroon, selected by a multistaged random sampling of primary care facilities in each region. The study will last for 9 months. A structured questionnaire will be used to collect general information concerning the health facility, laboratory and other departments involved in the HCT process. The investigators will directly observe at least 10 HIV testing processes in each facility and fill out the checklist accordingly.

ETHICS AND DISSEMINATION

Clearance has been obtained from the National Ethical Committee to carry out the study. Informed consent will be sought from the patients to observe the HIV testing process. The final study will be published in a peer-reviewed journal and the findings presented to health policy-makers and the general public.

Towards an ultra-rapid smartphone- connected test for infectious diseases

The development is reported of an ultra-rapid, point-of-care diagnostic device which harnesses surface acoustic wave (SAW) biochips, to detect HIV in a finger prick of blood within 10 seconds (sample-in-result-out). The disposable quartz biochip, based on microelectronic components found in every consumer smartphone, is extremely fast because no complex labelling, amplification or wash steps are needed. A pocket-sized control box reads out the SAW signal and displays results electronically. High analytical sensitivity and specificity are found with model and real patient blood samples. The findings presented here open up the potential of consumer electronics to cut lengthy test waiting times, giving patients on the spot access to potentially life-saving treatment and supporting more timely public health interventions to prevent disease transmission.

To err is human, to correct is public health: a systematic review examining poor quality testing and misdiagnosis of HIV status

INTRODUCTION

In accordance with global testing and treatment targets, many countries are seeking ways to reach the "90-90-90" goals, starting with diagnosing 90% of all people with HIV. Quality HIV testing services are needed to enable people with HIV to be diagnosed and linked to treatment as early as possible. It is essential that opportunities to reach people with undiagnosed HIV are not missed, diagnoses are correct and HIV-negative individuals are not inadvertently initiated on life-long treatment. We conducted this systematic review to assess the magnitude of misdiagnosis and to describe poor HIV testing practices using rapid diagnostic tests.

METHODS

We systematically searched peer-reviewed articles, abstracts and grey literature published from 1 January 1990 to 19 April 2017. Studies were included if they used at least two rapid diagnostic tests and reported on HIV misdiagnosis, factors related to potential misdiagnosis or described quality issues and errors related to HIV testing.

RESULTS

Sixty-four studies were included in this review. A small proportion of false positive (median 3.1%, interquartile range (IQR): 0.4-5.2%) and false negative (median: 0.4%, IQR: 0-3.9%) diagnoses were identified. Suboptimal testing strategies were the most common factor in studies reporting misdiagnoses, particularly false positive diagnoses due to using a "tiebreaker" test to resolve discrepant test results. A substantial proportion of false negative diagnoses were related to retesting among people on antiretroviral therapy. Conclusions HIV testing errors and poor practices, particularly those resulting in false positive or false negative diagnoses, do occur but are preventable. Efforts to accelerate HIV diagnosis and linkage to treatment should be complemented by efforts to improve the quality of HIV testing services and strengthen the quality management systems, particularly the use of validated testing algorithms and strategies, retesting people diagnosed with HIV before initiating treatment and providing clear messages to people with HIV on treatment on the risk of a "false negative" test result.